1. Field of the Invention
The present invention relates to a joint for tubular cable cover that joints a tubular cable cover which covers a cable such as a wire harness, and more particularly to a joint which restricts a displacement of a tubular cable cover which covers the cable.
2. Description of the Related Art
Conventionally, cables which constitute a wire harness arranged inside of an engine room of a vehicle are covered by a cylindrical tubular cable cover such as a so-called corrugated tube or a so-called spiral tube in order to protect the cables from heat and dust and, at the same time, to prevent the cables from coming into contact with peripheral parts.
For example, the corrugated tube is formed by molding using a synthetic resin material such as polypropylene which has an excellent shock resistance characteristic and an excellent wear resistance characteristic. The corrugated tube is formed in a thin cylindrical shape, has the bellow structure in which annular grooves and annular projections which extend in the circumferential direction are arranged at an equal pitch in the tube length direction, and has a favorable flexibility characteristic. A bundle of cables are placed inside the corrugated tube to thereby protect the cables. As the corrugated tube, there are types provided with a longitudinally extending slit and types not provided with such a longitudinally extending slit. The corrugated tube having the slit has been popularly used since it is capable of easily placing the cables therein.
In FIG. 19, there is shown a wire harness W which includes: a trunk line Wa which bundles a plurality of cables Wd; a branch line Wb which is branched from a branch portion We of the trunk line Wa; and a connector C which is mounted on a distal end portion of the branch line Wb for connection with electric equipments or various sensors. As shown in FIG. 19, three corrugated tubes T are exteriorly mounted on a portion between the connector C and the branch portion We and other portions for protecting the trunk line Wa and the branch line Wb.
Usually, in such a wire harness W, a length of the cable Wd and a length of the corrugated tube T which is exteriorly mounted on the cable Wd are manufactured under a strict length control. Particularly, lengths of the cables which are exposed from end portions of the corrugated tubes T (A, B in FIG. 19) are controlled such that a displacement of the corrugated tube T with respect to the cables is prevented.
However, at the time of actually wiring the cables in a vehicle or the like, the distance A between a rear end face of the connector C and an end face of the tube T and the distance B between end faces of the tubes T in the branch portion We are changed. In such a state, there exists a drawback that a displacement of the corrugated tube T with respect to the cables Wd is allowed. When the displacement of the corrugated tube T with respect to the cables Wd is allowed, due to the operation of an engine and other acoustic wave vibration, the wire harness W is resonated thus giving rise to a connection failure of terminals inside the connector C and, in a worst case, the disconnection of electric lines.
Therefore, conventionally, as shown in FIG. 20, at both end portions of the exteriorly mounted corrugated tube T, to restrict the generation of the displacement of the corrugated tube T with respect to an external force such as vibration, a tacky adhesive tape 21 is wound around the cable Wd which is exposed from the end portion of the tube T so as to fix the corrugated tube T (see JP-A-2002-078137). Further, as shown in FIG. 21, there has been also known a method in which a member 22 which makes a corrugated tube T and a connector C engage each other is separately provided so as to fix an end portion of the corrugated tube T to the connector C (see JP-A-2002-025684).
However, the restriction of the displacement of the corrugated tube T by the tape winding shown in FIG. 20 has a drawback that when the tacky adhesive tape 21 is used under an environment such as an engine room which is under a high temperature and a high humidity and is subjected to a considerable vibration for a long period (e.g. for 10 years), the tacky adhesive tape 21 is peeled off and the peeled-off tape 21 is entangled to a belt or the like. Further, since such a tape winding operation is cumbersome, the operation efficiency is poor thus making the reduction of the manufacturing cost of the wire harness difficult. Still further, since fixing by tape winding is weak, there exists a possibility that the displacement of the corrugated tube T is allowed.
Further, although the restriction of the displacement of the corrugated tube T using the engaging member 22 shown in FIG. 21 does not cause such a drawback attributed to tape winding, the provision of the engaging member 22 leads to the increase of a volume of the connector C. Such a volume increase of the connector C is not favorable in view of wiring of cables in the inside of the vehicle where the space efficiency is important. Further, assembling of the wire harness in a narrow space such as the inside of the engine room is deteriorated.